1. Field
The present disclosure relates to electrowetting display devices and methods of driving the same.
2. Description of the Related Art
Changes in the shape of liquid droplet when voltage is applied to the liquid droplet under certain conditions are called electrowetting. By using such an electrowetting phenomenon, for example, an electrowetting lens that electrically changes the focal length or an electrowetting scanner that electrically changes the refraction angle are now being developed.
An electrowetting display device makes use of such an electrowetting phenomenon. The electrowetting display device includes pixels, each having a structure in which oil colored with red, green, blue or black is disposed on a hydrophobic insulation layer. In such an electrowetting display device, when voltage is applied to each pixel, as the hydrophobic insulation layer (e.g., an insulation layer that resists mixture with water) changes into a hydrophilic insulation layer (e.g., an insulation layer that is soluble with water), the oil gathers on one side.
When no voltage is applied to each pixel, the oil is uniformly spread on the hydrophobic insulation layer. If a white reflective plate is disposed on the rear surface of an electrowetting display device, a pixel is colored with white when a voltage is applied to produce the hydrophilic insulation layer that causes the oil to gather on one side. In contrast, if a white reflective plate is disposed on the rear surface of an electrowetting display device, a pixel is tinted with the color of the oil when no voltage is applied.
The electrowetting display device may be manufactured into a transmissive type using a backlight unit or a reflective type using external light. A reflective type electrowetting display device has excellent visibility in strong outdoor sunlight and less power consumption, and furthermore has an excellent reproduction of natural colors because to produce colors oil is colored using dye. Accordingly, such an electrowetting display device can be applied to bendable electronic paper.